Validating an instrument
Flow verification is a procedure designed to ensure that your equipment or process is still doing what it was designed to do from the beginning.
Renger and his colleagues (12) described the validation of a specific analytical procedure for the analysis of theophylline in a tablet using high-performance thin layer chromatography (HPTLC).
Following this assessment, the meter or controller is then made to conform to the readings of the calibration standard within the stated accuracy specifications.
A primary calibration standard is directly measured against a reference standard provided by a bureau of standards, such as NIST. A secondary, or transfer, calibration standard is directly measured against this primary calibration standard in the lab and then serves in lieu of the primary standard in the field.
The AOAC (15) has developed a Peer-Verified Methods validation program with detailed guidelines on exactly which parameters should be validated.
Winslow and Meyer (16) recommend the definition and application of a master plan for validating analytical methods. Breaux and colleagues have published a study on analytical methods development and validation (17).